Throttling valve



F. E. SHELLY THROTTLING VALVE April l0, 1945. 2,373,268

File-d Dec, 15, 19424 ATTORNEYS y Patented Apr. 10, 1945 UNI-)TED s'm'msft PMENT OFFICE 2,373,268: Trmo'r'rLINGwnLvn-fr and"'fr`om"clsed position; Where' the Valve isk: *opmtnghelcmfmgmbr"qerefip large' andthe fluid pressureis'high a. greatdeal Vlded" a"a fum-her feamqf themvmtlolf' a ofjppweris requirednt Operate the Valve. Fup rotatable operati-ngimember :1n substantialahne mediate;ofzits.;endsandreciprocatefthe valvef tin-SAME fomedffwmffa comical Semi-ancona member.;by' .the :longitudinal movement; ofi ',a'icamn cem-,rid Withrth 115W? passage 3, andfmay-.Thavefi member extendingg-intoion througlfifsainzlv passager a mingen|5x01-other;meansfryconneetfn wat As a furtherifeaturefof luy-invention;the'camu50;.Supp1ye1men Th'enothV-Casingj Segent |2may Y- surface s :preferablyfa:Lcurxzedxoneesofthatizfomv have Similar-flanged 6 orioth'er Imeans Topcom equal increments of movement off;tlfecoperatingff-n meeting to a; deqivery- 1in-ef4 Igp-mayfals'ohhav@ i members,` there .ii/i111live:fproeressixzelyI .fgreatr'rim a flange 1 'for facilitating@theattachmentof the creznents 'of 'movement foi` :the walveanember' assit:- bonn'et @op i' capwholdigm thevawe-t stem; These ,f moves?? away-1' flOm-I its seatii' an'd i progressivelyifssll-partsimaybe1offfdrgingsiweldedftogetheri' In theflow passage I3 is a valve member 2| in the form of a. bullet suitably streamlined to reduce to a minimum, turbulence in the flow around the valve member. It is guidedfor axial movement in the line of flow in any suitable manner, as for instance by means of a pair of guides 22, disposed between the casing section I2 and the valve member 2| and disposed in opposed grooves of both. `'Ihey may tightly fit in the grooves of the casing section and'have a sliding t in the grooves of said valve member. The streamlining contour of the valve member may be determined in accordance with the character the contact rod 30, moves the valve member 2| to the left towards valve closure position shown in Fig. 1. As the valve member 2| moves towards seating engagement with the valve seat I4, the fluid pressure on said valve member 2| transmitted to the lower section of the cam member 25 increases. lThus the valve may be forced to its seat and against high head pressure, by the minimum force applied at the operating member.

In some cases the cam surfaces 21. and 28 may be straight, parallel, and at the desired angle togdirection of movement of the cam member,

- so that there will be equal endwise movement of '7^ the valve for equal endwise movement of the cam, but as a further feature of the improved a cam member extending-.into a transverseA passage 26 in rsaid valve member and havingits opposite sides presenting cam surfaces 21 and 28. These camsurfaces have cam follower engagement with the valvemember 2| substantially in the axial plane of said member, which is at right angles to the direction of movement of the cam member. It is highly desirable that the portions of the valve member vengaging the cam be Wear resistant. This is facilitated by the use of a pair of parallel cylindrical rods 3u and 3| which may` be hardened steel or softer steel surface hardened, and mounted in opposed grooves in opposite sides of the passage through the valve member. They may have a driving iltin the grooves or may be rotatable,but preferably they are securedby welding at one or at opposite sides. These two contact rods 30 and 3| are so disposed that their axes lie in the central axial plane of the valve member 2| and of the flow passage I3,A andthe two cam surfaces 21 and 28 are so designed as to engage one or the other or both of said rods at.

all times substantially along straight lines in said plane, so that the cam pressure is always applied in said plane and the forces are transmittedV equally tothe two guides 22. Although both cam surfaces may be surface hardened, it is more im-` portant that the cam 21 be surface hardened,

as it is the one toward the valve seat and subject to the greater pressure.V

For operating the cam member 25, the latter is provided at one end with a shank portion guided for axial'slide movement in a sleeve 36- and held against rotation by a key 31. The sleeve 35 may be held against rotation in the casing section I2 by a key 38. Threaded in to this shank 35 and extending axially thereof is a valve stem 39 passing through the bore of the valveloonnet I8 and having a suitable operating member such as a handle 40 at its outer end. The stem 39 is held against axial movement in any suitable or conventional manner, as for instance, byva collar 4| retained between an annular shoulder in the construction "'the surfaces are curved and converge so that for equal endwise movement of the camthere will be progressively shorter movements, as the valve approaches its seat.

To effect complete closure of the valve, the cam member 25 must bear with substantial force against the valve member 2|. The loading, therefore, of the cam member resulting fromv fluid pressure and valve seating reaction is ata maximum in closed position of the valve. With A the cam member 25 supported only Aat one end as a cantilever, the bending movements on said cam member resulting from this loading may, in some cases, be excessive. l

To relieve the strain on the upper support of the cam member 25 when the valve member 2|-. approaches closed position, I provide as an iin-v portant feature, an abutment or guide for.. the lower endl of said cam member opposite to the guided shank 35. This may continuously engage the cam member or engage it only when the'valve i member is near the end of its movement toward and to the seat. This abutment or guide is shown in the form of a pin.48 having a section 5I threaded through the wall of the casing section I2. The pin acts as a guide for the cam mem ber, as for instance by fitting into a hole at the end of the cam member 25. The outer end section 52 of the pin may be shaped to, receive a suitable turning tool. This abutment or guid" f ing and bracing pin 48 may be tapered at its outer.

end to facilitate its entry into the hole 50,11? the' pin is short enough so that it serves as an abutment only during a portion of the movementof the valve member 2|. The pin is shown ascirl cular in cross section'butY may be of any cross section shape as will offer the least resistance to the flow of fluid past it. f As many changes can be made in the above'A apparatus, and many apparently widely different embodiments of this invention can be made withl out departing from the scope of the claims, it is intended that all matter contained in the above valve bonnet I8 and a'locking ring 44 .threaded As the ,cam member 25 is moved downwardly I, from an open valve position by rotation of the handle 4D, the cam surface 21 bearing'against- .description or shown inthe accompanying draw!- ing shall be interpreted as illustrative and not Sina limiting sense. f 1

Applicants valve has the advantage of both'the conventional gate valve aridf'the conventional f globe valve without the disadvantage of either. A gate valve will give positive shuteoi, but cannot? beused very satisfactorily for throttling. On the l other hand, throttling can be secured with agl'obe valve, but it is not very eiective' from the stand-- point of positive shut-olf. Withapplicantsvalve, positive shut-off can be secured and also very effectivethrottling; 1 Another advantage, more particularly with'ree s. lation to applicants particular type of wedge is that this cam provides ya stronger constructionf.;

saale-,acs

than theusual: rotatable cams suchas havefbeen proposed7 in prior sart. Moreover, withfthe conventional .rotatable cam, it isdiicult `tozsecure locking of theicaml member, .since the camlsupporting element is not threaded, and this usually results 'in the necessity for r`additional `looking `mea'nszsuch-as worm gearing. .On the. other hand, .with applicants typexofca'm, the advantages lof a non-rising stemvalve are secured;'the*threads onthelstem being effective to lock the cam yin'any desiredv position.- i n l l Having thus described my invention, what I claim `as new :anddesire lto vsecure by ILetters Patent is: '1 f 1. A valve hav-ing a casing defining a flow passage and presenting a `seat substantially concentric with: said passage, a valve plugin said casing guided for movement towards v`or'away from said seat along the axis of the seat, and having'a recess intermediate its ends transversely of its path of movement, a cam extending into said recess and having engagement with said plug, means for moving said cam in a direction transversely of the path of movement of said plug to effect movement of said plug along said path, and means carried by said casing and independent of said valve plug for guiding said cam and for positively preventing rotation of said cam on its longitudinal axisduring said movement.

2. A valve having a casing defining a flow passage and presenting a seat, a bullet type of valve member in said casing and guided for endwise movement towards or away from said seat, a cam member in said casing and in engagement with said valve member, means for moving said cam member in a, direction at right angles to the direction of movement of said valve member to move said valve member while maintaining said cam vmember in follower engagement with said valve member, and a guide independent of said cam member carried by said casing and engaging said valve member for preventing rotation of said valve member about its longitudinal axis.

3. A valve having a casing defining a flow passage and presenting a seat, a valve member, means guiding said valve member for movement axially towards or away from said seat and operative to prevent rotation of the valve member about its longitudinal axis,'a cam engaging said valve member substantially in an axial plane of the valve `member, operating means for moving said cam endwise through said valve member to move the latter towards and away from said seat, and separate and independent guiding means carried by said casing for guiding said cam and for preventing rotation of said'cam about its axis of endwise movement.

4. A-valve having a casing presenting a seat, a valve member in said casing and having guided axial movement towards or away from said seat, said valve member having a passage extending transversely of its path of movement, said passage presenting opposed curved surfaces intermediate of the ends thereof, disposed transversely of the passage and extending transversely of the direction of movement of said valve member, and disposed in an axial plane of the valve member, a cam extending into said passage and having cam surfaces on opposite sides thereof facing the direction of movement of said valve member and having cam follower engagement with said curved surfaces in said passage, and means for moving said cam endwise through said passage while maintaining follower contact with said valvel member. in said planetomove said 'valve' member member at progressively` increasing rate faway from said seat, and at progressively .decreasing rate towards saidrseat for equal increments of endwise movement ofsaid operating member.

6. A valve having acasing presenting a seatpa valve member in said casing guided for movement towards or away from said seat, a vlongitudinally movable operating member, and a .transmission between said `operatingmember and saidlvalve member for movingsaid valve member towardsor away from said seat upon ,endwise actuationof said operating member, said transmission including means for progressively increasing the mechanical advantage of the power transmitted to said valve member from said operating member as said valve member is moved towards said seat and for progressively decreasing said mechanical advantage as said valve member is moved away from said seat.

7. A valve having a lcasing presenting a seat, a valve member in said casing guided for move ment towards or away from said seat, an endwise movable cam member having a convexedly curved cam surface in follower engagement with said valve member for forcing said valve member towards said seat as said cam member is moved in a direction at right angles to the path of movement of said valve member, and an operating member for moving said cam member, whereby said valve member is moved at progressively decreasing rate towards said seat for equal increments of movement of said operating member.

8. A valve having a casing presenting a seat, a

. valve member guided for movement towards or awai7 from said seat, a cam member having a con cavely curved cam surface in follower engagement with said valve member for forcing said valve member away from said seat as said cam member is moved in a direction at an angle to the direction of movement of said valve member, and an operating member for moving said cammember, whereby said valve member is movedy at progressively increasing rate away from said seat for equal increments of movement of said operating member. y

9. A valve having a casing defining a iiow passage and presenting a seatJ concentric with said flow passage, a valve plug in said casing guided for movement towards or away from said seat-substantially along the axis of the seat, a cam member having on its side facing the seat a convexedly curved cam surface and on the opposite side a ing rate away from said seat and progressivelyl increasing rate towards said seat for equal increments of movement of said operating member.

10. A valve having a casing defining a flow passage, and presenting a seat, a valve member in said casing guided for movement towards or away from said seat, a cam member having an overhanging unsupported section, and having a hole atthe free end of said unsupported cam section, means for moving said cam member longitudinally to operate said valve memberl towards or away from said seat, and a pinconnected to said casing and disposed in the path of movement of said hole, said pin entering said hole with a snug slide iit as said cam member approaches the 'limit of its valve closure position, whereby said cam section is supported by said pin against the reaction of said valve member. f

11i A valve having a casing presenting a seat, a valve. member in said casing guided for movement towards or away from said seat, a cam memrber Vhaving follower engagement withv said valve member to move said valve member towards or i f 4and around said stem. i

l2. A valve having a casing deningfa' flow n ,passage and presenting a seat, a valve member movable endwise toward and from the seat, acam member having a cam surface for engaging said valve member to move the latter toward and from said seat, said cam member being movablelin an endwise direction substantially at right angles to the direction of movement of said valve member, a guide on said casing and engaging Vsaid cam member for preventing rotation of the latter during said endwise movement, and a separateguide on said casing and engaging said valve member to prevent rotation of the latter about the axis of its endwise movement. 1w,

FRANKLIN E. SHELLY. 

